Book contents
- Frontmatter
- Contents
- Preface
- Part 1 Gravitation and relativity
- Part 2 Classical cosmology
- Part 3 Basics of quantum fields
- Part 4 The early universe
- 9 The hot big bang
- 10 Topological defects
- 11 Inflationary cosmology
- Part 5 Observational cosmology
- Part 6 Galaxy formation and clustering
- Hints for solution of the problems
- Bibliography and references
- Useful numbers and formulae
- Index
9 - The hot big bang
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Part 1 Gravitation and relativity
- Part 2 Classical cosmology
- Part 3 Basics of quantum fields
- Part 4 The early universe
- 9 The hot big bang
- 10 Topological defects
- 11 Inflationary cosmology
- Part 5 Observational cosmology
- Part 6 Galaxy formation and clustering
- Hints for solution of the problems
- Bibliography and references
- Useful numbers and formulae
- Index
Summary
Having given an overview of the relevant parts of particle physics, this section of the book now discusses in some detail the application of some of these fundamental processes in the early universe. The next three chapters increase in energy, starting here with ‘normal’ physics at temperatures up to about 1010 K, and moving on to more exotic processes in chapters 10 and 11.
Thermodynamics in the big bang
adiabatic expansion What was the state of matter in the early phases of the big bang? Since the present-day expansion will cause the density to decline in the future, conditions in the past must have corresponded to high density – and thus to high temperature. We can deal with this quantitatively by looking at the thermodynamics of the fluids that make up a uniform cosmological model.
The expansion is clearly adiathermal, since the symmetry means that there can be no net heat flow through any surface. If the expansion is also reversible, then we can go one step further, because entropy change is defined in terms of the heat that flows during a reversible change. If no heat flows during a reversible change, then entropy must be conserved, and the expansion will be adiabatic. This can only be an approximation, since there will exist irreversible microscopic processes.
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- Chapter
- Information
- Cosmological Physics , pp. 273 - 304Publisher: Cambridge University PressPrint publication year: 1998